Ollie Whitehouse, technical director of NCC Group, said: “The Health Service is by no means alone in facing this kind of attack.

“But NHS trusts are being increasingly targeted and any loss of patient data would be a nightmare scenario.”

Software security specialists Kaspersky Lab reported a 17.7 per cent rise in worldwide ransomware attacks in the 12 months leading up to March 2016, a total of 2.32 million upon an estimated 58 per cent of corporate PCs worldwide.